Istanbul - World Heritage sites - Basilica Cistern

Those Romans were clever fellows and their under ground water storage facilities another indication of that.

The cistern system is huge but just a small part of it is open to the public.  It would be a lovely place to be when trying to get away from the heat of summer.  As you descend you feel the temperature drop.

There is about a meter of water in the reservoir but while it was in use the water would be up to the top of the columns.  In the water huge Carp swim about looking for a feed.

Some of the columns have decoration on them - don't know if they serve a particular purpose.